Editing Hyperpigmentation (section)

===Diseases and conditions===
Hyperpigmentation is associated with a number of diseases or conditions, including the following:

*[[Addison's disease]] and other sources of [[adrenal insufficiency]], in which hormones that stimulate melanin synthesis, such as [[melanocyte-stimulating hormone]] (MSH), are frequently elevated.
*[[Cushing's disease]] or other excessive [[adrenocorticotropic hormone]] (ACTH) production, because MSH production is a byproduct of ACTH synthesis from [[proopiomelanocortin]] (POMC).
*[[Acanthosis nigricans]]—hyperpigmentation of [[intertriginous]] areas associated with [[insulin resistance]].
*[[Melasma]], also known as '[[chloasma]]' or the “mask of pregnancy,” when it occurs in pregnant women.— It is a common skin problem that causes dark discolored patchy hyperpigmentation. It typically occurs on the face and is symmetrical, with matching marks on both sides of the face. The condition is much more common in women than men, though men can get it too. According to the [[American Academy of Dermatology]], 90 percent of people who develop melasma are women.<ref>{{cite web | url = https://www.aad.org/public/diseases/color-problems/melasma | title = Melasma | publisher = American Academy of Dermatology, Inc.}}</ref>
*[[Acne vulgaris|Post-acne marks]] from post-inflammatory hyperpigmentation.
*[[Linea nigra]]—a hyperpigmented line found on the [[abdomen]] during [[pregnancy]].
*[[Peutz–Jeghers syndrome]]—an [[autosomal dominant]] disorder characterized by hyperpigmented [[macules]] on the lips and oral mucosa and gastrointestinal [[polyp (medicine)|polyps]].
*Exposure to certain chemicals such as [[salicylic acid]], [[bleomycin]], and [[cisplatin]].
*[[Smoker's melanosis]]
*[[Coeliac disease]]
*[[Cronkhite–Canada syndrome]]
*[[Porphyria]]
*[[Tinea]] fungal infections such as [[ringworm]].
*[[Haemochromatosis]]—a common but debilitating genetic disorder characterized by the chronic accumulation of [[Iron (element)|iron]] in the body.
*[[Mercury poisoning]]—particularly cases of cutaneous exposure resulting from the topical application of mercurial ointments or skin-whitening creams.
*[[Aromatase deficiency]]
*[[Nelson's syndrome]]
*[[Graves' disease]]
*Schimke immunoosseous dysplasia (SOID).<ref>{{Cite web|url=https://rarediseases.info.nih.gov/diseases/4984/schimke-immunoosseous-dysplasia|title=Schimke immunoosseous dysplasia {{!}} Genetic and Rare Diseases Information Center (GARD) – an NCATS Program|website=rarediseases.info.nih.gov|access-date=2019-03-13|archive-date=2017-10-25|archive-url=https://web.archive.org/web/20171025181658/https://rarediseases.info.nih.gov/diseases/4984/schimke-immunoosseous-dysplasia|url-status=dead}}</ref>
*As a result of [[tinea cruris]].
* Due to [[B12 deficiency]].<ref>{{Cite journal| title=Cutaneous lesions and vitamin B12 deficiency: An often-forgotten link, Rajendran Kannan, MB BS MD| year=2008| pmc=2294086| last1=Kannan| first1=R.| last2=Ng| first2=M. J.| journal=Canadian Family Physician| volume=54| issue=4| pages=529–532| pmid=18413300}}</ref>
* [[Atopic dermatitis]] as a result of inflammation.<ref>{{Citation |last1=Lawrence |first1=Elizabeth |title=Postinflammatory Hyperpigmentation |date=2022 |url=http://www.ncbi.nlm.nih.gov/books/NBK559150/ |work=StatPearls |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=32644576 |access-date=2022-03-27 |last2=Al Aboud |first2=Khalid M.}}</ref>

Hyperpigmentation can sometimes be induced by [[dermatological]] [[laser]] procedures.